Apparatus for testing tires and the like



p 1965 R. w. OBARSKI APPARATUS FOR TESTING TIRES AND THE LIKE 3Sheets-Sheet 1 Filed Sept.

INVENTOR. RICHARQ \IV. OBARSK| ATTYS.

Sept. 21, 1965 R. w. OBARSKI 3,206,973

APPARATUS FOR TESTING TIRES AND THE LIKE Filed Sept. 24, 1962 3Sheets-Sheet 2 FIG. 2

INVENTOR. RICHARD W. OBARSKI ATTYS.

p 1965 R. w. OBARSKI 3,206,973

APPARATUS FOR TESTING TIRES AND THE LIKE INVENTOR. RICHARD W. OBARSKIATTYS.

United States Patent 3,206,973 APPARATUS FOR TESTING TIRES AND THE LIKERichard W. Obarski, Stow, Ohio, assignor to Adamson United Company,Summit, Ohio, a corporation of Ohio Filed Sept. 24, 1962, Ser. No.225,576 7 Claims. (Cl. 73-146) This invention relates to apparatus fortesting tires and other rotary members, and, more particularly, it isconcerned with simplified apparatus of this type.

Various types of testing apparatus of the character described have beenprovided heretofore, but known machines are open to the objection thatelaborate and cumbersome linkages have often been utilized to measureloading forces, and these usually involve frictional inaccuracies of anamount so that small, but perhaps significant improvement in the rotarymember being tested cannot be recognized or determined. Moreover, knownmachines have tended to become so large and complicated that they arevery expensive.

It is the general object of the present invention to avoid and overcomethe foregoing and other difliculties of and objections to prior knownequipment by the provision of apparatus characterized by simplicity andinexpensiveness of construction, but possessing extremely accurate andsensitive load measuring arrangements whereby improvements of small butsignificant amounts in the rotary member being tested can be recognizedand measured.

Another object of the invention is the provision of pneumatictire-testing apparatus requiring a minimum of floor space, and pitdimensions, but adapted to handle tires of a wide variety of sizes.

Another object of the invention is the provision of testing apparatusfor rotary members wherein errors arising from gravity forces, frominertia forces in the load measuring system, and from trying to performtoo many different operations upon a single apparatus are eliminated ormaterially reduced.

Other objects of the invention are to provide apparatus of the typedescribed wherein force measuring cells are positioned ahead of pointsof friction, wherein the cells can be preloaded, wherein the cells canbe cut out of operation without removing them, and wherein floatingaligning means are provided to allow for dimensional changes.

The foregoing objects of the invention, and other objects which willbecome apparent as the description proceeds, are achieved by theprovision of apparatus for testing tires and the like and including aflywheel, means for rotating the flywheel, a bed extending in the planeof the flywheel, a carriage slidably mounted on the bed, means foradjustably moving the carriage toward and from the flywheel, a Y-shapedarm, means pivotally mounting the arm in vertically extending positionon the carriage on an axis parallel to the axis of the flywheel, meanspivotally mounted on the carriage and pivotally connected to the arm foreffecting swinging movement of the top of the arm toward and from theflywheel, a link pivotally mounted on the upper end of each branch ofthe Y- shaped arm, each link being pivoted on an axis parallel to theaxis of the flywheel, an axle carried by the upper ends of the linksparallel to the axis of the flywheel, a rotary member to be testedrotatably carried by the axle, and force measuring cells positionedbetween the upper ends of the links and the upper ends of the branchesof the Y-shaped arm.

For a better understanding of the invention, reference should be had tothe accompanying drawings wherein:

FIG. 1 is a side elevation of apparatus incorporating the principles ofthe invention;

3,206,973 Patented Sept. 21, 1965 FIG. 2 is a plan view of the apparatusof FIG. 1;

FIG. 3 is an end elevation of the apparatus of FIGS. 1 and 2;

FIG. 4 is an enlarged fragmentary View of the load cell portion of FIG.1 with parts broken away to better illustrate the construction; and

FIG. 5 is an enlarged fragmentary view of a portion of FIG. 4 showingthe means for transmitting the force to the load cell.

In the drawings, the numeral 10 indicates a relatively large and heavyflywheel, typically of a diameter of 67.226 inches which is 1/300 of amile per revolution of the flywheel. The flywheel 1 is rotatably mountedabout a horizontal axis 11 by means of brackets 12 and is adapted to berotated at a selected speed by adjustable driving means 13.

The brackets 12 are mounted upon a base 14 and extending laterallytherefrom is a bed indicated as a whole by the numeral 16 which includesa pair of rectangular beams 18 joined together at their outer ends by aheader 20. Carried between the header 20 and the base 14 are a pair oftubes 22 which slidably support a carriage 24 for movement towards andfrom the base 14. The position of the carriage 24 on the bed 16 isnormally controlled by means of a screw 26 rotatably supported in theheader 20 and threaded through a nut 28 secured to the carriage 24.Thus, when the squared end 30 of the screw 26 is rotated by means of adetachable wrench 32, the carriage 24 is moved towards and from the base14 of the apparatus.

The carriage 24 is provided with a pair of bracket bearings 34 whichpivotally support a Y-shaped arm indicated as a Whole by the numeral 36.The bearings 34 receive trunnions 40 on the arm 36 and position the axis38 of the arm 36 parallel with the axis 11 of the flywheel 10.

The lower end of the arm 36 is pivotally secured at 42 to a piston rod44 of a hydraulic cylinder 46 pivotally mounted near its center on axis48 by means of downwardly extending brackets 50 supported on theunderside of the carriage 24.

The upper branches 52 and 54 of the Y-shaped arm 36 each pivotallysupports a relatively short and light weight link indicated generally bynumeral 56 about an axle 58a on lower ends 56b of the links 56. The axle58 is on an axis 58a which is also parallel to the axis 11 of theflywheel 10. The upper ends 56a of the links 56 removably carry an axle60 having square mounting ends to prevent rotation thereof. A tire T orother rotary member to be tested is rotatably mounted on the axle 60.Removable bearing caps 68 secure the axle 60 to the links 56. Positionedbetween the upper ends 56a of the links 56 and the upper branches 52 and54 of the Y-shaped arm 36 are force measuring cells 62, capable ofstanding the maximum load applying the tire T against the flywheel 10,for example, 10,000 pounds maximum. The force measuring cells 62 areusually electrical in character and electric leads (not shown) areemployed to bring the electrical change in condition of the cells toappropriately calibrated force measuring means (not shown).

To assist in maintaining the movement of the links 56 toward and fromthe pressure cells 62 in a substantially frictionless manner and tosupport the links 56 against any movement which would tend to bind thelinks 56 on the free pivotal movement about their axes 58, the upperends of the branches 54 and 52 of the Y-shaped arm 36 are hollowed outon the side toward the flywheel 10 as indicated by the dotted line 52aon branch 52 in FIGURE 1 and FIGURE 3 and by the dotted line 54a onbranch 54 in FIGURE 3. A pair of rollers 64 are rotatably mounted to theinner side walls of the branches 52 and 54 on either side of the links56. These rollers 64 being normally spaced from wear plates 66 carriedon the sides of the links 56. The clearance between the rollers 64 andwear plates 66 is small so that should transient side loading conditionsdevelop causing the links 56 to deflect at 90 to the applied tire loadthe rollers 64 engage wear plates 66 and prevent further deflection.

Referring to FIG. 5, in the preferred practice of the invention theforce measuring cells 62 are preloaded, usually some -15 percent, so asto take up any lost motion in the mechanism. This is accomplished bysecuring a rod 74 in each link 56 which rod extends freely through abore 76 in the upper branches 52 and 54 of the Y-shaped arm 36. Acompression spring 78 surrounds the rod 74 and engages between thebranch 52 and a nut 80 threaded on the rod. Adjustment of the nuts 80thereby gives a preloading to the force measuring cells 62 and takes alllost motion out of the load measuring system. This preloading can becompensated for in the actual load indicating instruments, as will bewell understood. The preloading does not interfere with the applicationof load forces against the force measuring cells 62.

In addition, the preloading means function to take hammering andvibration out of the force transmitting system such as will sometimesoccur during test, for example, if the flywheel is cleated. Thepreloading means can also be utilized to take the force measuring cellsentirely out of the system all without physically removing the cells.When this is done, cap screws 81 are extended through holes in a flangeon nut 80, each screw carrying a spacer washer 83. Then tightening downthe screws 81 forces the washers 83 against the branch 52 and 54 therebymaking each link 56 integral through'stud 74 with its associated branch52, 54 of the Y-shaped arm 36. This taking of the force measuring cells62 out of the system is sometimes desirable when the flywheel isprovided with very heavy cleats or with posts or plugs which engage, forexample, a tire. Loading forcescan then be measured, less accurately, bythe pressure applied to the cylinder 46.

Turning now to FIG. 5, means are provided to prevent misalignment of theload forces, and these means comprise a button 82 having a socket-likeopening 84 engaging with and partially encapsulating the rounded end ofthe pin or column 86 extending from the force measuring cell 62. Thebutton 82 is received in a recess 88 in the side of the link 56, therebeing appropriate clearance between the sides of the button and therecess to provide automatic alignment of parts by way of the floatingseat action even in the event of dimensional changes in any parts.

It will be recognized that the structure described posi tions the loadmeasuring cells 62 ahead of substantially all points of friction in theapparatus, and with the loading force holding the tire against theflywheel being directly taken by the load cells. The inertia andfriction of the links 56 is a minimum. The load cells can be used onlyto indicate the load, or can be used to hold the load to a selectedamount, as will be understood.

In the operation of the apparatus described, the tire T to be tested isrotatably mounted upon the axle 60, and the axle 60. is positioned inthe upper ends of the links 56, being secured therein by removablebearing caps 68. Now the carriage 24 is moved towards the .base 14 so asto position the tire T very near to the surface of the flywheel 10. In atypical test, simulating the loading of a tire, the flywheel is broughtup to the desired speed after the hydraulic cylinder 46 is operated toswing the Y- shaped arm 36 to apply the tire T against the surface ofthe flywheel with the desired approximate load. The exact load of thetire T against the flywheel 10 is determined during the entire run ofthe test by the reading on the pressure cells 62. During the period ofthe test, the Y- shaped arm 36 should be in a substantially verticalposition so that gravitational forces are substantially eliminated onthe load measuring system. Additionally, keeping the arm 36 verticalinsures that the plane passing through the axis 11 and the centerline ofload cells 62 also contains the point of tangency between the flywheel10 and the tire T and contains the axis of axle 60. The position of thecarriage 24, as effected by the rotation of the screw 26 is selected sothat the Y-shaped arm 36 is in the position recited during tests.

It will be understood that various other tests on a rotary member can beperformed in addition to the one specifically mentioned which simulatesthe loading of a tire upon a roadway. It will be evident that theloading of the tire against the flywheel can be gradually increased orgradually decreased during a test. It is also possible to measurevertical loadings upon a tire during a test by building a pressure cell72 into each link 56 where one side of each cell 72 is connected toupper ends 56a of the links 56 and the other side is connected to thelower ends 56b of the links 56. In this instance the ends 56a and 56bwill be connected only by the cell 72 so that all vertical movementtherebetween will be transferred to the cell 72 to indicate verticalloading. It is to be noted that the axis 11 of the flywheel 10 and theaxis of rotation of the tire T are parallel to each other andhorizontally in alignment.

While in accord with the patent statutes, one best known embodiment ofthe invention has been illustrated and described in detail, it is to beparticularly understood that the invention is not to be limited theretoor thereby, but that its scope is defined in the appended claims.

What is claimed is:

1. Apparatus for testing tires and the like and including a flywheel ona horizontal axis, means for rotating the flywheel, a bed extendinghorizontally in the plane of the flywheel, a carriage slidably mountedon the bed, hand operated screw means for adjustably moving the carriagetoward and from the flywheel, a Y-shaped arm, means pivotally mountingthe arm near the middle thereof and vertically extending on the carriageon an axis parallel to the axis of the flywheel, a hydraulic motorpivotally mounted on the underside of the carriage and pivotallyconnected to the lower end of the arm for effecting swinging movement ofthe top of the arm toward and from the flywheel, a link pivotallymounted on the upper end of each branch of the Y-shaped arm, each linkbeing pivoted on an axle parallel to the axis of the flywheel, an axlecarried by the upper ends of the links parallel to the axis of theflywheel adapted to rotatably carry the tire to be tested, forcemeasuring cells positioned between the upper ends of the links and theupper ends of the branches of the Y-shaped arm, roller means carried bythe upper ends of the branches of the Y-shaped arm for supporting thelinks in the event of transient side loading in the movement thereofabout their pivotal axes, and means for controllably preloading theforce measuring cells.

2. Apparatus for testing tires and the like and including a flywheel,means for rotating the flywheel, a bed extending in the plane of theflywheel, a carriage slidably mounted on the bed, means for adjustablymoving the carriage toward and from the flywheel, a Y-shaped arm, meanspivotally mounting the arm near the middle thereof and verticallyextending on the carriage on an axis parallel to the axis of theflywheel, a hydraulic motor pivotally mounted on the underside of thecarriage and pivotally connected to the lower end of the arm foreffecting swinging movement of the top of the arm toward and from theflywheel, a link pivotally mounted on the upper end of each branch ofthe Y-shaped arm, each link being pivoted on an axis parallel to theaxis of the flywheel, an axle carried by the upper ends of the linksparallel to the axis of the flywheel adapted to rotatably carry the tireto be tested, force measuring cells positioned between the upper ends ofthe links and theupper ends of the branches of the Y-shaped armproviding a positive stop for the links in the movement thereof abouttheir pivotal axes, and floating seat means for effecting alignmentbetween each force measuring cell and each link.

3. Apparatus for testing tires and the like and including a flywheel,means for rotating the flywheel, a bed extending in the plane of theflywheel, a carriage slidably mounted on the bed, means for adjustablymoving the carriage toward and from the flywheel, a Y-shaped arm, meanspivotally mounting the arm on the carriage on an axis parallel to theaxis of the flywheel, means pivotally mounted on the carriage andpivotally connected to the arm for elfecting swinging movement of thearm toward and from the flywheel, a link pivotally mounted on the upperend of each branch of the Y-shaped arm, each link being pivoted on anaxis parallel to the axis of the flywheel, an axle carried by the upperends of the links parallel to the axis of the flywheel adapted torotatably carry the tire to be tested, force measuring cells positionedbetween the upper ends of the links and the upper ends of the branchesof the Y-shaped arm, roller means carried by the upper ends of thebranches of the Y-shaped arm for supporting the links in the event oftransient side loads in the movement thereof about their pivotal axes,and means for locking each link with each branch of the Y-shaped arm tocut each force measuring cell out of operation.

4. Apparatus for testing tires and the like and including a flywheel,means for rotating the flywheel, a bed extending in the plane of theflywheel, a carriage slidably mounted on the bed, means for adjustablymoving the carriage toward and from the flywheel, a Y-shaped arm, meanspivotally mounting the arm on the carriage on an axis parallel to theaxis of the flywheel, means pivotally mounted on the carriage andpivotally connected to the arm for effecting swinging movement of thearm toward and from the flywheel, a link pivotally mounted on the upperend of each branch of the Y-shaped arm, each link being pivoted on anaxis parallel to the axis of the flywheel adapted to rotatably carry thetire to be tested, and force measuring cells positioned between theupper ends of the links and the upper ends of the branches of theY-shaped arm.

5. Apparatus for testing tires and the like and including a rotaryflywheel, means mounting the tire to be tested for movement to and fromthe flywheel means for moving the mounting means to apply the tire to betested against the flywheel with a selected loading, and pressure cellmeans carried by the mounting means and taking the load applying thetire to be tested against the flywheel for indicating the loading on thetire to be tested, said pressure cell means measuring the load in twodiflerent directions, the directions being substantially at right anglesto each other.

6. Apparatus for testing tires and the like and including a rotaryflywheel, means mounting the tire to be tested for movement to and fromthe flywheel, means for moving the mounting means to apply the tire tobe tested against the flywheel with a selected loading, said mountingmeans including a pair of relatively short and light weight linksrotatably supporting the tire to be tested, force measuring cellslimiting the movement of the links, and means resiliently and adjustablyholding the links against the cells to preload the cells.

7. Apparatus for testing tires and the like and including a rotaryflywheel, means mounting the tire to be tested for movement to and fromthe flywheel, and means for moving the mounting means to apply the tireto be tested against the flywheel with a selected loading, said mountingmeans including a pair of relatively short and light weight linksrotatably supporting the tire to be tested, force measuring cellslimiting the movement of the links.

References Cited by the Examiner UNITED STATES PATENTS 1,068,180 7/13Sonntag 73-8 1,588,343 6/26 Stevens 738 2,367,838 1/45 Allen 73-72,722,587 11/55 Buzzetti et al. 7388.5 X 2,869,361 1/59 Powell et a1.73146 RICHARD C. QUEISSER, Primary Examiner.

JOSEPH P. STRIZAK, Examiner.

1. APPARATUS FOR TESTING TIRES AND THE LIKE AND INCLUDING A FLYWHEEL ONA HORIZONTAL AXIS, MEANS FOR ROTATING THE FLYWHEEL, A BED EXTENDINGHORIZONTALLY IN THE PLANE OF THE FLYWHEEL, A CARRIAGE SLIDABLY MOUNTEDON THE BED, HAND OPERATED SCREW MEANS FOR ADJUSTABLY MOVING THE CARRIAGETOWARD AND FROM THE FLYWHEEL, A Y-SHAPED ARM, MEANS PIVOTALLY MOUNTINGTHE ARM NEAR THE MIDDLE THEREOF AND VERTICALLY EXTENDING ON THE CARRIAGEON AN AXIS PARALLEL TO THE AXIS OF THE FLYWHEEL, A HYDRAULIC MOTORPIVOTALLY MOUNTED ON THE UNDERSIDE OF THE CARRIAGE AND PIVOTALLYCONNECTED TO THE LOWER END OF THE ARM FOR EFFECTING SWINGING MOVEMENT OFTHE TOP OF THE ARM TOWARD AND FROM THE FLYWHEEL, A LINK PIVOTALLYMOUNTED ON THE UPPER END OF EACH BRANCK OF THE Y-SHAPED ARM, EACH LINKBEING PIVOTED ON AN AXLE PARALLEL TO THE AXIS OF THE FLYWHEEL, AN AXLECARRIED BY THE UPPER ENDS OF THE LINKS PARALLEL TO THE AXIS OF THEFLYWHEEL ADAPTED TO ROTATABLY CARRY THE TIRE TO BE TESTED, FORCEMEASURING CELLS POSITIONED BETWEEN THE UPPER ENDS OF THE LINKS AND THEUPPER ENDS OF THE BRANCKES OF THE Y-SHAPED ARM, ROLLER MEANS CARRIED BYTHE UPPER ENDS OF THE BRANCHES OF THE Y-SHAPED ARM FOR SUPPORTING THELINKS IN THE EVENT OF TRANSIENT SIDE LOADING IN THE MOVEMENT THEREOFABOUT THEIR PIVOTAL AXES, AND MEANS FOR CONTROLLABLY PRELOADING THEFORCE MEASURING CELLS.